1. Field of the Invention
The present invention relates to a device for continuously casting steel including a continuous casting mold supported in a lifting table and oscillating in the casting direction and at least one oscillation drive acting on the lifting table.
2. Description of the Related Art
Hydraulic oscillation drives for lifting tables of continuous casting plants are known in the art. The drives produce an oscillation of the mold with any desired speed curves, for example, in accordance with an asymmetrical sinusoid. The technical background for influencing the oscillation movement of the lifting table and, thus, of the mold, is the desire to extend the lubricating time between the mold wall and the strand skin and to obtain an optimum negative strip time. These effects advantageously influence the oscillation mark formation, particularly the oscillation mark depth. In addition, the temperature constancy of the strand skin is improved over the entire width of the mold.
For example, DE 43 41 719 C1 discloses a device for continuously casting steel including a continuous casting mold which oscillates in the casting direction and is connected to a hydraulic oscillation drive which, in addition to the usual sinusoidal oscillation curves, also permits oscillation curves having a different shape. The continuous casting mold is mounted at spring stacks which are fixedly mounted and pretensioned at both ends and extend transversely of the casting direction, wherein these spring stacks are provided on both sides of the continuous casting mold laterally next to the short side plates. Arranged in the middle between the stacks of springs arranged one on top of the other is a fastening block each under which is arranged an oscillation drive constructed as a servo hydraulic cylinder and, thus, the oscillation drive is composed of two cylinders. The fastening blocks transmit the oscillation movement carried out by the hydraulic cylinders to the mold attached to the fastening blocks.
Also known in the art is an oscillation device for a continuous casting mold with a so-called parallelogram lever system. Parallel levers which support the mold table with the mold are pivotably guided at a bearing housing. Several hydraulic cylinders are provided for producing an oscillating movement of the continuous casting mold. The servo cylinders are anchored in a stationary manner to their base plate and are connected in an articulated manner through their piston rods to the mold table. The lateral displacement of the mold table is compensated by an elastic connecting element.
A disadvantage of the parallelogram lever system is the large amount of space required for installing such an oscillation device in an existing continuous casting plant.